The sintered NdFeB magnet is mainly produced as per custom design, so there are no standard sizes. Because it is hard and brittle, it is hard to make construction part with sintered NdFeB magnets. The magnets could be made into the following shape: disc or cylinder, cuboids, ring, arc segment and other special shape.
Please provide the following information if you need to order.

Material grade required.
Size and shape, if available, a sketch or drawing with dimensions and tolerances.
Max working temperature.
Delivered magnetized or un-magnetized? Magnetization direction?
Quantities required.
Coating required (if any)
Information on what you want to use the magnet for.